希腊正教会（希腊语：Ελληνορθόδοξη Εκκλησία，英语：Greek Orthodox Church）是东罗马帝国国家教会分裂后，东罗马正教会的几个教会统称，其神学根植于初期教父以及拜占庭文化，礼拜仪式使用通用希腊语。与普世牧首共融。其起源于近东的初期基督教以及拜占庭帝国，今天的东正教修道最重要的中心为在埃及西奈半岛的圣凯瑟琳修道院和以及马其顿的阿索斯山。

东西教会大分裂时与罗马天主教会各分东西，并斯拉夫正教会等正教会共融成为东正教会。

The name Greek Orthodox Church (Greek: Ἑλληνορθόδοξη Ἑκκλησία, Ellinorthódoxi Ekklisía, IPA: [elinorˈθoðoksi ekliˈsia] or Greek Orthodoxy) is a term referring to the body of several Churches within the larger communion of Eastern Orthodox Christianity, whose liturgy is or was traditionally conducted in Koine Greek, the original language of the New Testament, and whose history, traditions, and theology are rooted in the early Church Fathers and the culture of the Byzantine Empire. Greek Orthodox Christianity has also traditionally placed heavy emphasis and awarded high prestige to traditions of Christian monasticism and asceticism, with origins in Early Christianity in the Near East and in Byzantine Anatolia. Today, the most important centres of Christian Orthodox monasticism are Saint Catherine's Monastery in the Sinai Peninsula (Egypt) and Mount Athos in Greek Macedonia (Northern Greece).